It is known that the use of fatty acid soap compositions in water containing calcium and/or magnesium ions leads to the deposition of insoluble lime soap and that this deposition is conducive to the scum frequently seen in sinks and bathtubs. The use of a detergent as a lime soap dispersant can prevent this deposition, but lime soap dispersants that have previously been used in soap compositions have not been sufficiently efficient.
Both sodium cocoyl glyceryl sulfonate and N-alkyl-N,N-dimethylamine oxides having 8-20 carbons in the alkyl group are known surfactants. However, the amine oxides have not found wide application in the formulation of toilet soap bars because of having been available only as dilute aqueous solutions which lead to a decomposition problem when the excess water is removed at normal evaporation temperatures and which lead to a frothing problem when the excess water is removed at lower temperatures under vacuum.
As taught in copending application Ser. No. 415,910 (Smith et al.), filed Oct. 2, 1989, it has now been found possible to prepare solid N-alkyl-N,N-dimethylamine oxides in a practical manner. Thus, the use of the amine oxides in the formulation of soap bars has become more attractive.